Levias

Levias is a giant whale-like creature floating in The Sky, more specifically, in the Thunderhead. He is the guardian of the Sky, making sure that no monsters from the Surface harm anyone.[1] He is first seen in the game overrun by a parasite, and Link must defeat it to help heal him. After Link defeats the parasite, he will have to get parts of the Song of the Hero from the three dragons: Faron, Eldin, and Lanayru and finally return to Levias for the final part of the song.[2]

References

↑ "There is an 80% probability that you can get information about the Triforce from Levias, the great spirit of the skies." — Fi, Skyward Sword.

↑ "Well done, Master. You've successfully collected three parts of the Song of the Hero.
I recommend you return to the sky and meet with the great sky spirit, Levias, to complete the song." — Fi, Skyward Sword.